Telephone.



PATENTED SEPT. 4, 1906.

J. Z. MILLER.

TELEPHONE.

APPLICATION FILED 00130, 1902.

muTnn STATES JOHN Z. MILLER, OF ERIE, PENNSYLVANIA.

TELEPHONE.

Specification of Letters Patent.

Patented Sept. 4.-, 1906;

Application filed October 30.1902. Serial No. 129,484.

To all Hill/07771 it uny concern.-

Be it known that I, JOHN Z. MILLER, a citizen of the United States, residing at Erie, in the county of Erie and State of Pennsyl vania, have invented new and useful Improvements in Telephones, of which the fol lowing is a specification.

This invention relates to telephone systems; and it consists in certain improvements in the construction thereof, as will be hereinafter fully described, and pointed out in the claims.

More particularly, the invention relates to a selective system-that is, a system wherein two parties may be connected with one metallic circuit and call the exchange or be palled without calling the other party on said It further consists in a calling mechanism which is peculiarly designed for this selective system, but which may be used with other systems to advantage.

The invention is illustrated in the accompanying drawings, wherein A marks a sin le telephone which is shown simply to show t 1e manner of connection with the telephones on the selective system. Extending from this telephone are the line-wires a a, and bridged in the circuit by the wire a a is a call-drop a for this telephone. Upon a call from the telephone A the drop a operates in the usual manner to indicate a call and the party from whom the call is sent. Upon receiving this call the ordinary plug 0 is placed in the jack a. This jack a is of any ordinary construction and is connected with the line-wires a a. The cord-circuit C, connected with the plug 0, has bridged in it the circuit d, which connects with the springs (1 cl, forming members of the operators telephone-switch. As soon as the plug 0 is placed in the jack the operator throws the lever E, pressing the springs d d into contact with the stationary members (Z d of the operators telephone-switch, thus completing the connection between the central telephone D with the cord-circuit through the circuit D.

Central being connected with the callingtelephone A ascertains the party to be called, which for convenience we will assume is the telephone B. This being ascertained, the other plug a of the cord-circuit is placed .in the jack 6. This jack is connected with the line-wire 6 6 formed in a circuit with the telephone B. Following the cord-circuit C,

it will be noted that it passes through the I switch members a c? by the spring members 0" c and by the extended cord-circuit C to the plug 0. The operator having placed the plugc in the jack b throws the lever E, operators key between the springs c 0", thus opening the cord-circuit and throwing the springs c 0 against the generator switch members 6 e. The switch members (2 are connected by the line E E and E E with the generator E l/Vhen, therefore, the switch E is thrown so as to bring the spring members a in contact with the generator members 6, the call-telephone is cut out and the called telephone B is thrown into the circuit. It will be noted in following the circuit E E that it runs to the second telephone switch members e e by the spring members 6 e and from the switch to the generator by the circuit E At the called telephone B there is bridged between the talking-circuit b b the ringer-circuit B in which there is an impedance-coil B Also bridged in with this impedance-coil is the ringer B The energy of the generator is sufficient to operate the ringer B through the impedance-coil. This coil has preferably about two thousand ohms resistance, and this is sufficient to cut this line B out of the talking-circuit when it is connected. It also fulfils other purposes, which will be hereinafter mentioned. If, however, the call A should desire the telephone B, then the oper ator would connect the line b b in the manner hereinafter described. Before operating the lever E for throwing in the generator and cutting out the calling-circuit the operator would throw the lever E" of the operators special key. This would spread the spring members 6 e and throw the spring member 6 into contact with the ground member 6*. It would thus connect one side of the genera tor through the member 6 c" with the ground at 6 The spring member 6 would contact a spring generator member 6 and this in turn would contact the generator member e. The members 6 and c are both bridgedinto the generator-circuit E E by wires E, and the member 6'' is then connected with the opposite side of the generator from that connected with the ground at 6 After throwing the lever E, as described, and connecting both wires E with one side of the generator the operator throws the lever E. This cuts out the caller and connects both the line-wires b b with the one side of the generator. These lines pass to the talking-circuit formed by the lines B B of the telephone B. Bridged across the lines B B is a line B, in which are arranged the impedance-coils B B The ringer-line B is connected with the line B' between the impedance-coils. The circuit passes to the ground B through the ringer B It will be noted that the lines I) b are balanced, so that this call does not effect the ringer B of the telephone B. On the other hand, it will be noted that when the talking-circuit of the telephone B is closed the impedance coils B B obstruct the connection with the ground, and thus prevent any annoyance from this source.

Where a call is sent in to the central station from either the telephone B or B, the ringer of the other of these telephones is not affected. For instance, if a call is sent in from the telephone B the ringer B of the telephone B is out of circuit and the current passes directly to the drop J of the telephone-exchange, the drop J being bridged in the circuit formed by the lines I2 I2 Again, if a call is sent in from the telephone B the resistance of the impedance-coil B being much greater than that of the drop J prevents the action of the ringer B Furthermore, the nature of the impulsesfias hereinafter .described, tend to this result. In addition to this the impedance-- coil B is made of much greater resistance than the coil of the ringer B There a connection is made between the telephone B and the telephone A, should the telephone A ring off or before the connection is broken send in a call with the intention of getting another connection, the telephone B would not respond, for the reason that the ringer B of said telephone is out of circuit. On the other hand, if "the telephone A were connected with the telephone B the telephone B would not respond to such a call from the telephone A. To accomplish and to eifect this, I provide the ring-out drop G which is bridged in the cord-circuit by the circuit C This drop is of comparatively low resistance and high impedance, so that in View of the high resistance of the impedance-coil B the energy incident to a call from the telephone A is taken care of through the drop C As a further element of safety in this respect I make the resistance of ringer B very small in comparison with the impedance coilsay forty ohms.

I prefer to use the automatic call mechanism herein shown. This is adapted to any telephone system, but particularly adapted to this telephone system, especially the telephone B, in relation to the ringer of the telephone B when a call is sent in from the telephone B. The hook H is arranged to normally carry the receiver F, as ordinarily. The hook is pivoted at h and is arranged at the completion of its movement to close switch h and throw into circuit the receiver F and transmitter G by means of the wire B ,which completes the circuit through the receiver, transmitter, and hook. Extending from the hook is an arm or lever h to which a spring W is attached. The spring k is of suflicient strength to swing the hook on the pivot h when the receiver is removed, but is not of suflicient strength to hold the hook when opposed by the weight of the receiver. The hook is provided with the quadrant H Arranged on this is a series of serrations If. These are arranged to contact an insulated button I on the spring member I and to press said spring member as the hook passes upwardly into contact with the stationary member of the switch I so that said switch is closed and opened as the insulated button I passes from serration to serration. The switch formed by the members I and I is in a circuit i which passes through the primary coil I of an induction-coil. It also passes through and is energized by a source of electrical supply, preferably by a local battery I Arranged on the quadrant H is a switch-contact h A switch member I is arranged to be acted on by the contact k With the ini tial movement of the hook this switch member I is connected through the hook-wire B with the line-wire 6 It is also connected through the wire 1', secondary coil I, wire 1), and wire B with the line-wire b Thus the line-circuit is closed by the switch I through the secondary coil I of the induction-coil. Through this arrangement the line-wire is subjected to the impulses incident to the making and breaking of the circuit through the primary coil I as the button I passes over each serration h. This induced current is much stronger than a direct current, and thus makes more certain the operation of the drop J upon a call from the telephone. A single impulse would ordinarily effect this result, but as an element of safety several impulses are provided through the several serrations h Upon the completion of the move ment of the hook the spring-switch I passes by the surface 72, and throws the secondary coil out of the circuit. The button I also preferably passes by the last serration, so as to throw out the primary coil. In order that the hook will have a steady motion under the action of the spring 7L2, I provide the dash-pot H, which prevents too rapid a movement. This call system is peculiarly adapted to the selective system herein v shown. The ringer B- is composed of the spools b and 6 The armature b is pivoted at b". A spring I) is attached to the armature and tends to hold it in contact with the core of the spool b With the armature in this position the clapper is near or in contact with the gong b of the rmger.

The impulse incident to the closing of the circuit through the primary coil is less than that incident to the breaking of said circuit.

The winding of the spools b and b is arranged so that the impulse due to closing the circuit through the primary coil tends to move the armature into contact with the core of the spool b. This impulse is not sullicient to overcome the spring and effect this result. 011 the other hand, the stronger impulse due to breakin the primary circuit is ineffective, because the armature normally rests in contact with the core 6. The station-generator of course creates sullicient energy to operate the ringer, notwithstanding the opposition of the spring 6 I do not claim in this application the automatic switch structure actuated with the hook, as this forms the subject-matter of a separate application filed by me July 30, 1903, Serial No.167,6e5, as a division of this application.

What I claim as new is-- 1. In a selective telephone system, the combination with two line-wires; of two telephones connected with said line-wires, said line-wires forming a metallic circuit for said telephones, one of said telephones having its ringer bridged with an impedance-coil across themetallic circuit, the resistance of the impedance-coil being greater than that of the coils of the ringer, and the other of said telephones having its ringer connected with both wires of the circuit and the ground; an exchange-generator; and switches for throwing the generator into the metallic circuit for actuating the ringer of the telephone having its ringer bridged across said circuit, and for throwing the generator into connection with both line-wires for one side of the circuit and through the ground for ringing the other of said telephones.

2. In a selective telephone system, the combination with two line-wires of two telephones connected with said line-wires, said line-wires forming a metallic circuit for said iJGlGPlIOUGS, one of said telephones having its ringer bridged with an impedance-coil across said circuit, and the other of said telephones having its ringer connected with both wires of said circuit and the ground; an exchangegenerator and switches for throwing the generator into the metallic circuit for actuating the ringer of the telephone having its ringer bridged across said circuit, and for throwing the generator into connection with both linewires for one side of the circuit throu h the ground for ringing the other of said telephones; and a cord-circuit at the exchange, said cord-circuit being provided with a coil of less resistance than the impedance-coil of said telephone.

3. In a selective telephone system, the combination of the wires 1) and b forming a metallic circuit; the telephone B having a ringer B bridged across the circuit with an i1npedance-coil B, the impedance-coil being of greater resistance than the coil of the ringer; the telephone B also connected with the line 6 b the ringer B connected with both the wires l) b on one side and the ground at the other side; the impedance-coils B B at each side of the ringer B an exchange-generator E and switches for throwing the wires b b into circuit with the generator for actuating the ringer B and for throwing both the wires 6 6 into connection with one side of the generator and closing said circuit through the ground for actuating the ringer B 4. In a selective telephone system, the combination of the wires 0 and b forming a metallic circuit; the telephone B having a ringer B bridged across said circuit with an impedance-coil, the impedance-coil being of greater resistance than the coil of the ringer; the telephone B also connected with the line b b on one side and the ground at the other side; the impedance-coils B B? at each side of the ringer B; an exchange-generator E the switch actuated by the lever E for connecting the generator with the wires I) b and the special switch comprising the members 0 a connected with the line-circuit the spring members 0 e, the members a 0 through which both sides of the line-circuit are connected with one side of the generator, and the member 0 through which the other side of the generator is connected with the ground.

5. In a selective telephone system, the combination of the wires 1) and b forming a metallic circuit; the telephone B having a ringer B bridged across the circuit with an impedance-coil B the impedance-coil being of greater resistance than the coil of the ringer; the telephone B also connected with the line b b on one side and the ground on the other side; the impedance-coils B B at each side of the ringer B an exchange-generator E and switches for throwing the wires 1) 6 into circuit wit-h the generator for actuating the ringer B and for throwing both the wires 6 b into connection with one side of the generator and closing said circuit through the ground for actuating the ringer B a cordcircuit in the exchange; and a coil in said circuit of less resistance than the impedancecoil B In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

JOHN Z. MILLER.

WVitnesses:

H. C. LORD, MARGARET SULLIVAN. 

